PEM water electrolysis for hydrogen production:fundamentals,advances,and prospects

Hydrogen,as a clean energy carrier,is of great potential to be an alternative fuel in the future.Proton exchange membrane(PEM)water electrolysis is hailed as the most desired technology for high purity hydrogen production and self-consistent with volatility of renewable energies,has ignited much attention in the past decades based on the high current density,greater energy efficiency,small mass-volume characteristic,easy handling and maintenance.To date,substantial efforts have been devoted to the development of advanced electrocatalysts to improve electrolytic efficiency and reduce the cost of PEM electrolyser.In this review,we firstly compare the alkaline water electrolysis(AWE),solid oxide electrolysis(SOE),and PEM water electrolysis and highlight the advantages of PEM water electrolysis.Furthermore,we summarize the recent progress in PEM water electrolysis including hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)electrocatalysts in the acidic electrolyte.We also introduce other PEM cell components(including membrane electrode assembly,current collector,and bipolar plate).Finally,the current challenges and an outlook for the future development of PEM water electrolysis technology for application in future hydrogen production are provided.

Interfacial engineering of atomic platinum-doped molybdenum carbide quantum dots for high-rate and stable hydrogen evolution reaction in proton exchange membrane water electrolysis

Platinum(Pt)-based electrocatalysts remain the only practical cathode catalysts for proton exchange membrane water electrolysis(PEMWE),due to their excellent catalytic activity for acidic hydrogen evolution reaction(HER),but are greatly limited by their low reserves and high cost.Here,we report an interfacial engineering strategy to obtain a promising low-Pt loading catalyst with atomically Pt-doped molybdenum carbide quantum dots decorated on conductive porous carbon(Pt-MoCx@C)for high-rate and stable HER in PEMWE.Benefiting from the strong interfacial interaction between Pt atoms and the ultra-small MoCx quantum dots substrate,the Pt-MoCx catalyst exhibits a high mass activity of 8.00 A·mgPt−1,5.6 times higher than that of commercial 20 wt.%Pt/C catalyst.Moreover,the strong interfacial coupling of Pt and MoCx substrate greatly improves the HER stability of the Pt-MoCx catalyst.Density functional theory studies further confirm the strong metal-support interaction on Pt-MoCx,the critical role of MoCx substrate in the stabilization of surface Pt atoms,as well as activation of MoCx substrate by Pt atoms for improving HER durability and activity.The optimized Pt-MoCx@C catalyst demonstrates>2000 h stability under a water-splitting current of 1000 mA·cm^(−2)when applied to the cathode of a PEM water electrolyzer,suggesting the potential for practical applications.